Solicitor Christopher Stewart-Moore released a statement with the news the Medical Committee of the French authority are planning a hearing.

The statement, issued to Press Association Sport, said: "On behalf of Frankie Dettori I can confirm that, as a consequence of a positive test at Longchamp on September 16 2012, he will be the subject of an inquiry by the Medical Committee of France Galop next week.

"In compliance with, and out of respect for, the regulations of France Galop, he will not be commenting further until the France Galop procedures have been completed."

Dettori had four rides at Longchamp on September 16, a day of major trials for the Prix de l'Arc de Triomphe meeting the following month.

The Italian partnered Marco Botti's Joshua Tree to finish third in the Qatar Prix Foy, while the John Hammond-trained Sarah Lynx trailed home last in the Prix Vermeille.

He was then beaten just a head into second on Godolphin's Farhh in the Prix du Moulin and was third for his former employers on Willing Foe in the Prix Gladiateur.

France Galop have not commented on proceedings and in previous similar cases they have not issued a statement before the hearing.

Dettori made the headlines last month when his 18-year association with Godolphin came to an end, with the jockey planning to ride as a freelance in 2013.

The 41-year-old partnered nine English Classic winners in the royal blue silks, including their first in 1994 Oaks victor Balanchine, and a total of 110 Group or Grade One winners for the owner.

A host of Dettori's big-race winners have been trained by Godolphin handler Saeed bin Suroor, including four of those that formed the rider's 'Magnificent Seven' at Ascot on September 28, 1996.

He had recently been sharing the Godolphin rides with fellow retained jockeys Mickael Barzalona and Silvestre de Sousa before the split.